There isn't much to be said for jet lag. True, for those travelling westwards, it does add an early-morning shift to the working day, useful when deadlines are tight; and it's a help when you want to catch the first lift at a distant resort, and have some driving to do first. But the only occasion on which I have risen at 4am with a smile on my face was on a trip to the Fairmont Banff Springs hotel in Canada. There, the excellent deli is open all night, which gives wide-awake, hungry European and Japanese guests a chance to meet up and discuss the meal that they think they're eating.

For an entirely different reason, however, I didn't resent waking at the same time in the Montbleu Resort Casino and Spa at South Lake Tahoe, in Nevada.

At 6,300ft above sea level, and four hours' drive east of San Francisco, Lake Tahoe is the largest Alpine lake in North America. It is surrounded by mountains, and skiing. Of its 15 ski areas, some are known to British skiers (most of the big ones, including Heavenly and Squaw Valley) and some are not (hills such as Soda Springs and Donner Ski Ranch). Drive clockwise around the lake, a major summer-season destination, and the resorts evolve from colonies of hippie cabins in the north-west corner near Truckee into luxury, second-home developments in the south-west. Further along the same route one-way only for tour buses, which treat the lake as a roundabout with a circumference of 70 miles you come to South Lake Tahoe, where in the lakeside glades are motels whose age and styles (namely, the Fifties and Sixties) make them ripe for rediscovery.

Finally, in the lake's south-east corner, everything changes. Here, still in South Lake Tahoe, is an area of huge, slab-sided resort hotels. The schism occurs along an invisible borderline, that between California and Nevada. The wooded glades, and two-thirds of the entire lakeside, are in California, the land of Merlot, hybrid cars and Apple computers; the gas-guzzling tower blocks are on the dark side, in Nevada, a place of gambling dens and legalised brothels.

It's a safe bet that a jet-lagged guest wandering around one of South Lake Tahoe's old motels at 4am would be greeted by little more than dim lights, low music and maybe a whiff of patchouli oil. But at that time of night the "lobby" of the Montbleu Resort in Nevada is a blazing cacophony of energy consumption.

For British skiers used to drawing up outside cosy hotels in Austrian mountain villages, arriving weakened by a 12-hour flight and a four-hour drive at the Montbleu is a mouth-opener. Ostensibly, the place is a hotel; in reality, it is a casino with rooms. Tucked into an obscure corner of the gaming room, which by my estimate contains 676 slot machines, is a reception desk. And right over in the far corner, beyond the "sexy" lingerie shop and the coach-tour desks, are the elevators to the bedrooms.

It is the ski area above South Lake Tahoe that is called Heavenly.

Elsewhere, the name might seem presumptuous; but in this setting, with the hellishness that lies below, it's fair enough. The view that rolls out in front of you, as the gondola rises from near the lakeside, is celestial. There is always something wonderful about ski areas that overlook large expanses of water: The Remarkables above Queenstown in New Zealand, Le Massif in Canada, Faraya Mzaar in Lebanon. From the heights of Heavenly, the view is big enough to encompass not only Lake Tahoe but also the big, dry Carson Valley, across a ridge to the east; what grabs the attention, though, is the 191 square miles of dark, still freshwater, and its surrounding mountains.

The skiing, on the largest ski area alongside the lake, is good, especially for intermediates. Like South Lake Tahoe, it spreads across the state line, being split fairly equally between Nevada and California. Happily, the difference between them is not so apparent at 10,000ft, although signposts do make the transition clear.

Poor snow at the beginning of this year made the challenging slopes at the extreme of the Nevada side in the Mott and Killebrew Canyons inaccessible when I was at Heavenly. But the better-known expert area on the California side, the East Bowl, was open. It owes its reputation partly to Glen Plake, the most familiar face in American skiing, thanks to the huge Mohican that soars up from his shaven scalp. Plake, who inaugurated the annual ski marathon on the bowl's bumpy Gunbarrel route, was skiing the slope with his father. Despite appearances, Plake who serves as a sort of ambassador for Heavenly, with the title "Ski.E.O" is as sharp as a knife when you meet him.

In terms of style, Plake is a throwback. But by comparison with the entertainers performing down in the casinos, he is both young (at 43) and cutting-edge. Last month a headliner at Harrah's, the big-name casino, was the singer Chubby Checker. You may not be familiar with his work, but he had a big hit in 1960: "The Twist". He was less chubby then.

Heavenly has something of a chequered history. A summer resort since the late-19th century, Lake Tahoe became easily accessible only in the 1940s, when the state of California upgraded the highway. The first ski area opened in 1953, under the delightful name of Bijou Park Ski Way; and it was this that formed the basis of what was to become Heavenly. After enduring financial problems that took it to the brink of bankruptcy, and several high-profile, accidental deaths (including that of Sonny Bono, who skied into a tree in 1998), Heavenly was purchased by the Wall-Street-quoted Vail Resorts corporation. In 2002, the new owner embarked on an investment programme that has continued into this season. The new, high-speed Olympic Express is three times faster than the old lift I rode in January; and improved snow-making means that, given cold weather, the ski area should have better snow cover this season than last.

Vail Resorts has also created a new "village" (ie shops, restaurants and accommodation) at the gondola base. That's on the California side; across the state line, it's a different story. There, in the big, old hotels, the drinking, smoking and gambling crowd predominates, creating an unhealthy atmosphere that endures for 24 hours a day. Before I went to Heavenly, a friend recommended visiting the lobby of one of the Nevada resort hotels very late at night. And since I was awake, and only a few floors away, I did.

Soon after four in the morning, there were seven gamblers at the gaming tables, and another six dotted around the lobby playing the machines. The absence of bodies meant that the carpet in which an orange-and-blue spiral pattern and Russian Constructivist forms are combined to emetic effect was all the more visible. By comparison, the flashing lights of the slot machines seemed almost calming. Their visuals had a variety of rather odd themes, among them Clint Eastwood films, supermarkets and the destruction of Pompeii. The most common one, however, was the simple Wheel of Fortune. With a sound-and-light show unmatched by anything less than a major police incident, the machines displayed unfeasibly large cash prizes that might be won, in the unlikely event that the wheel of fortune did not favour the casino.

An attractive woman sat alone at the bar. This was, I gathered, a staff post: there was always a single woman at the bar, but not always the same one. No one was sitting in the 24-hour restaurant, because it was closed.

I made my gloomy way back to the elevators. As I passed the lingerie shop, a mannequin pointed two inches of nipple at me and said: "People like this place! It's you: you're just no fun." Maybe, but next time I know what I'll do at Heavenly. I'll stay on the California side and just lie awake at 4am, listening to my new iPod. It's new, because the old one was stolen from my room at the Montbleu. I suppose that's what happens when you're surrounded by chancers.

Stephen Wood travelled with Ski Independence (0845 310 3030; www.ski-i.com), which offers packages to Heavenly, including British Airways flights from Heathrow to San Francisco, 4x4 car hire, and seven nights at the Embassy Suites on the California side of South Lake Tahoe, from 1,035 per person, based on two sharing, for departures on 22 January